Process for fireproofing and waterproofing textiles



?atented ept. 1 3.931

HAROLD R. OFFORD AND NICHOLAS 'l. MIROV,

or ERKELEY; oamronnra PROCESS FOR FIREPROOFING AND WATERPROOFING TEXTILES No Drawing.

Application filed July 24, 1929. Serial No. 380,742.

(GRANTED UNDER THE AC'I. OF MARCH 3, 1883, AS AMENDED AIPRIL 30, 1928;370 0. G. 7 57) This application is made under the act approved April30, 19:28, and the invention herein described may be manufactured andused by or for the Government for governmental purposes without paymentto us of any royalty thereon.

We hereby dedicate the invention herein described. to the free use ofthepublic, to take effect upon the granting of a patent to us.

This invention relates to a combined process for fire-proofing andwaterproofing fabrics and leather goods and is particularly adapted foruse by persons engaged in spraying chemicals such as chlorates,perchlorates, per-sulphates etc... which form combustible mixtures withclothing materials made of cotton, Wool or silk or with leather goods.

The invention comprises a method first described by Perkins for theinitial fireproofing process and combines with it'tre'atment of thematerial to be protected by means of a waterproofing process namely anatural asphalt dissolved in a rapidly volatile solvent.

A fireproofing or a waterproofing process alone does'not give adequateprotection if cloth is subsequently sprayed with or soaked in sodiumchlorate. The combined process however renders the fibre.'fla1ne-proofand then provides an impermeable layer about the fibre which preventsthe chemical in water solution from soaking into the fibre.

Cloth treated by the combination process is absolutely spark-proof,cannot be ignited by friction and allows the surface chemical to burnoff slowly Without a rapid burning of the cloth.

The combined process is described as follows: (1) Material is thoroughlysoaked in a Tw. (Twaddells h'ydrometer degree readings, or 27 Baum)solution of sodium stannate, and then squeezed (squeezing is veryimportant) and-dried. The material is then passed through a 15 Tw. (or10 Baum) solution of ammonium sulphate, again r squeezed and driedWithout rinsing. A further treatment with cold water is advised in orderto remove (2) The material is dried again andthen thorougly soaked in agilsonite-benzene solution to 1 gram of gilsonite per 100 cc. of

in a proportionate the soluble sodium sulphate.

commercial coal tar benzene). The cloth is again squeezed. and air drieduntil the excess solvent has v'olatilized. Cloth that is being wornorsubjected to any frictional action may require a further waterproofingtreatment. One treatment with the fireproofing materials is sufficient.Textiles so treated may be washed repeatedly without impairing thewaterproofing or fireproofing processes. Gilsonite' is a natural asphaltwhich is. mined in Utah and is available in unlimited amounts.

\Ve claim:

A. process for fireproofing and waterproofing fibrous and othermaterials con- .sisting of immersing the materials in a 45 Tw. solutionof sodium stannate, squeezing and drying the materials, soaking the saidmaterials in a 15 Tw. solution of ammonium sulphate, squeezing anddrying the said materials, removing the soluble sodium sulphate bydipping in cold water, drying and then thoroughly soaking the saidmaterials solution of not more than 1 gr. of gilsonite in 100 cc. ofbenzene, and squeezing and air drying the said materials until theexcess solvent has volatilized.

H. R. OFFORD.

NICHOLAS T. MTROV

